Air conditioning units for buses often require that the evaporator and condenser sections thereof mount in the rear roof area of a bus without detracting from passenger head room in the passenger compartment, without significantly increasing the height of the bus, and without unduly complicating normal service procedures. These requirements are coupled with an additional restraint when the bus has a rear window, as the bus air conditioning unit must not interfere with rear window area. Also, the air in the passenger compartment is directed through a closed air flow path which includes the bus air conditioning unit, and it is then returned to the passenger compartment after conditioning. This flow path includes an evaporator and air moving means such as a blower. Noise generated in the closed air flow path by the air moving means should be prevented from entering the passenger compartment.
Thus, it would be desirable, and it is the object of the invention, to provide a new bus air conditioning unit, and to provide new methods of directing air through the bus air conditioning unit, which meet all the above stated requirements.